/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 * .blend file reading entry point
 */

/** \file blender/blenloader/intern/readblenentry.c
 *  \ingroup blenloader
 */


#include <stddef.h>

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <math.h>

#include "MEM_guardedalloc.h"

#include "BLI_utildefines.h"
#include "BLI_path_util.h"
#include "BLI_ghash.h"
#include "BLI_linklist.h"
#include "BLI_listbase.h"
#include "BLI_string.h"

#include "DNA_genfile.h"
#include "DNA_sdna_types.h"


#include "BKE_main.h"
#include "BKE_library.h" // for BKE_main_free
#include "BKE_idcode.h"

#include "BLO_readfile.h"
#include "BLO_undofile.h"
#include "BLO_blend_defs.h"

#include "readfile.h"

#include "BLI_sys_types.h" // needed for intptr_t

#ifdef WIN32
#  include "BLI_winstuff.h"
#endif

/* local prototypes --------------------- */
void BLO_blendhandle_print_sizes(BlendHandle *, void *);

/* Access routines used by filesel. */

/**
 * Open a blendhandle from a file path.
 *
 * \param filepath The file path to open.
 * \param reports Report errors in opening the file (can be NULL).
 * \return A handle on success, or NULL on failure.
 */
BlendHandle *BLO_blendhandle_from_file(const char *filepath, ReportList *reports)
{
	BlendHandle *bh;

	bh = (BlendHandle *)blo_openblenderfile(filepath, reports);

	return bh;
}

/**
 * Open a blendhandle from memory.
 *
 * \param mem The data to load from.
 * \param memsize The size of the data.
 * \return A handle on success, or NULL on failure.
 */
BlendHandle *BLO_blendhandle_from_memory(const void *mem, int memsize)
{
	BlendHandle *bh;

	bh = (BlendHandle *)blo_openblendermemory(mem, memsize, NULL);

	return bh;
}

void BLO_blendhandle_print_sizes(BlendHandle *bh, void *fp)
{
	FileData *fd = (FileData *) bh;
	BHead *bhead;

	fprintf(fp, "[\n");
	for (bhead = blo_firstbhead(fd); bhead; bhead = blo_nextbhead(fd, bhead)) {
		if (bhead->code == ENDB)
			break;
		else {
			const short *sp = fd->filesdna->structs[bhead->SDNAnr];
			const char *name = fd->filesdna->types[sp[0]];
			char buf[4];

			buf[0] = (bhead->code >> 24) & 0xFF;
			buf[1] = (bhead->code >> 16) & 0xFF;
			buf[2] = (bhead->code >> 8) & 0xFF;
			buf[3] = (bhead->code >> 0) & 0xFF;

			buf[0] = buf[0] ? buf[0] : ' ';
			buf[1] = buf[1] ? buf[1] : ' ';
			buf[2] = buf[2] ? buf[2] : ' ';
			buf[3] = buf[3] ? buf[3] : ' ';

			fprintf(fp, "['%.4s', '%s', %d, %ld ],\n", buf, name, bhead->nr, (long int)(bhead->len + sizeof(BHead)));
		}
	}
	fprintf(fp, "]\n");
}

/**
 * Gets the names of all the datablocks in a file of a certain type (e.g. all the scene names in a file).
 *
 * \param bh The blendhandle to access.
 * \param ofblocktype The type of names to get.
 * \param tot_names The length of the returned list.
 * \return A BLI_linklist of strings. The string links should be freed with malloc.
 */
LinkNode *BLO_blendhandle_get_datablock_names(BlendHandle *bh, int ofblocktype, int *tot_names)
{
	FileData *fd = (FileData *) bh;
	LinkNode *names = NULL;
	BHead *bhead;
	int tot = 0;

	for (bhead = blo_firstbhead(fd); bhead; bhead = blo_nextbhead(fd, bhead)) {
		if (bhead->code == ofblocktype) {
			const char *idname = bhead_id_name(fd, bhead);

			BLI_linklist_prepend(&names, strdup(idname + 2));
			tot++;
		}
		else if (bhead->code == ENDB)
			break;
	}

	*tot_names = tot;
	return names;
}

/**
 * Gets the previews of all the datablocks in a file of a certain type (e.g. all the scene previews in a file).
 *
 * \param bh The blendhandle to access.
 * \param ofblocktype The type of names to get.
 * \param tot_prev The length of the returned list.
 * \return A BLI_linklist of PreviewImage. The PreviewImage links should be freed with malloc.
 */
LinkNode *BLO_blendhandle_get_previews(BlendHandle *bh, int ofblocktype, int *tot_prev)
{
	FileData *fd = (FileData *) bh;
	LinkNode *previews = NULL;
	BHead *bhead;
	int looking = 0;
	PreviewImage *prv = NULL;
	PreviewImage *new_prv = NULL;
	int tot = 0;

	for (bhead = blo_firstbhead(fd); bhead; bhead = blo_nextbhead(fd, bhead)) {
		if (bhead->code == ofblocktype) {
			const char *idname = bhead_id_name(fd, bhead);
			switch (GS(idname)) {
				case ID_MA: /* fall through */
				case ID_TE: /* fall through */
				case ID_IM: /* fall through */
				case ID_WO: /* fall through */
				case ID_LA: /* fall through */
				case ID_OB: /* fall through */
				case ID_GR: /* fall through */
				case ID_SCE: /* fall through */
					new_prv = MEM_callocN(sizeof(PreviewImage), "newpreview");
					BLI_linklist_prepend(&previews, new_prv);
					tot++;
					looking = 1;
					break;
				default:
					break;
			}
		}
		else if (bhead->code == DATA) {
			if (looking) {
				if (bhead->SDNAnr == DNA_struct_find_nr(fd->filesdna, "PreviewImage") ) {
					prv = BLO_library_read_struct(fd, bhead, "PreviewImage");
					if (prv) {
						memcpy(new_prv, prv, sizeof(PreviewImage));
						if (prv->rect[0] && prv->w[0] && prv->h[0]) {
							unsigned int *rect = NULL;
							size_t len = new_prv->w[0] * new_prv->h[0] * sizeof(unsigned int);
							new_prv->rect[0] = MEM_callocN(len, __func__);
							bhead = blo_nextbhead(fd, bhead);
							rect = (unsigned int *)(bhead + 1);
							BLI_assert(len == bhead->len);
							memcpy(new_prv->rect[0], rect, len);
						}
						else {
							/* This should not be needed, but can happen in 'broken' .blend files,
							 * better handle this gracefully than crashing. */
							BLI_assert(prv->rect[0] == NULL && prv->w[0] == 0 && prv->h[0] == 0);
							new_prv->rect[0] = NULL;
							new_prv->w[0] = new_prv->h[0] = 0;
						}

						if (prv->rect[1] && prv->w[1] && prv->h[1]) {
							unsigned int *rect = NULL;
							size_t len = new_prv->w[1] * new_prv->h[1] * sizeof(unsigned int);
							new_prv->rect[1] = MEM_callocN(len, __func__);
							bhead = blo_nextbhead(fd, bhead);
							rect = (unsigned int *)(bhead + 1);
							BLI_assert(len == bhead->len);
							memcpy(new_prv->rect[1], rect, len);
						}
						else {
							/* This should not be needed, but can happen in 'broken' .blend files,
							 * better handle this gracefully than crashing. */
							BLI_assert(prv->rect[1] == NULL && prv->w[1] == 0 && prv->h[1] == 0);
							new_prv->rect[1] = NULL;
							new_prv->w[1] = new_prv->h[1] = 0;
						}
						MEM_freeN(prv);
					}
				}
			}
		}
		else if (bhead->code == ENDB) {
			break;
		}
		else {
			looking = 0;
			new_prv = NULL;
			prv = NULL;
		}

	}

	*tot_prev = tot;
	return previews;
}

/**
 * Gets the names of all the linkable datablock types available in a file. (e.g. "Scene", "Mesh", "Lamp", etc.).
 *
 * \param bh The blendhandle to access.
 * \return A BLI_linklist of strings. The string links should be freed with malloc.
 */
LinkNode *BLO_blendhandle_get_linkable_groups(BlendHandle *bh)
{
	FileData *fd = (FileData *) bh;
	GSet *gathered = BLI_gset_ptr_new("linkable_groups gh");
	LinkNode *names = NULL;
	BHead *bhead;

	for (bhead = blo_firstbhead(fd); bhead; bhead = blo_nextbhead(fd, bhead)) {
		if (bhead->code == ENDB) {
			break;
		}
		else if (BKE_idcode_is_valid(bhead->code)) {
			if (BKE_idcode_is_linkable(bhead->code)) {
				const char *str = BKE_idcode_to_name(bhead->code);

				if (BLI_gset_add(gathered, (void *)str)) {
					BLI_linklist_prepend(&names, strdup(str));
				}
			}
		}
	}

	BLI_gset_free(gathered, NULL);

	return names;
}

/**
 * Close and free a blendhandle. The handle becomes invalid after this call.
 *
 * \param bh The handle to close.
 */
void BLO_blendhandle_close(BlendHandle *bh)
{
	FileData *fd = (FileData *) bh;

	blo_freefiledata(fd);
}

/**********/

/**
 * Open a blender file from a pathname. The function returns NULL
 * and sets a report in the list if it cannot open the file.
 *
 * \param filepath The path of the file to open.
 * \param reports If the return value is NULL, errors indicating the cause of the failure.
 * \return The data of the file.
 */
BlendFileData *BLO_read_from_file(
        const char *filepath,
        ReportList *reports, eBLOReadSkip skip_flags)
{
	BlendFileData *bfd = NULL;
	FileData *fd;

	fd = blo_openblenderfile(filepath, reports);
	if (fd) {
		fd->reports = reports;
		fd->skip_flags = skip_flags;
		bfd = blo_read_file_internal(fd, filepath);
		blo_freefiledata(fd);
	}

	return bfd;
}

/**
 * Open a blender file from memory. The function returns NULL
 * and sets a report in the list if it cannot open the file.
 *
 * \param mem The file data.
 * \param memsize The length of \a mem.
 * \param reports If the return value is NULL, errors indicating the cause of the failure.
 * \return The data of the file.
 */
BlendFileData *BLO_read_from_memory(
        const void *mem, int memsize,
        ReportList *reports, eBLOReadSkip skip_flags)
{
	BlendFileData *bfd = NULL;
	FileData *fd;

	fd = blo_openblendermemory(mem, memsize,  reports);
	if (fd) {
		fd->reports = reports;
		fd->skip_flags = skip_flags;
		bfd = blo_read_file_internal(fd, "");
		blo_freefiledata(fd);
	}

	return bfd;
}

/**
 * Used for undo/redo, skips part of libraries reading (assuming their data are already loaded & valid).
 *
 * \param oldmain old main, from which we will keep libraries and other datablocks that should not have changed.
 * \param filename current file, only for retrieving library data.
 */
BlendFileData *BLO_read_from_memfile(
        Main *oldmain, const char *filename, MemFile *memfile,
        ReportList *reports, eBLOReadSkip skip_flags)
{
	BlendFileData *bfd = NULL;
	FileData *fd;
	ListBase old_mainlist;

	fd = blo_openblendermemfile(memfile, reports);
	if (fd) {
		fd->reports = reports;
		fd->skip_flags = skip_flags;
		BLI_strncpy(fd->relabase, filename, sizeof(fd->relabase));

		/* clear ob->proxy_from pointers in old main */
		blo_clear_proxy_pointers_from_lib(oldmain);

		/* separate libraries from old main */
		blo_split_main(&old_mainlist, oldmain);
		/* add the library pointers in oldmap lookup */
		blo_add_library_pointer_map(&old_mainlist, fd);

		/* makes lookup of existing images in old main */
		blo_make_image_pointer_map(fd, oldmain);

		/* makes lookup of existing video clips in old main */
		blo_make_movieclip_pointer_map(fd, oldmain);

		/* make lookups of existing sound data in old main */
		blo_make_sound_pointer_map(fd, oldmain);

		/* removed packed data from this trick - it's internal data that needs saves */

		bfd = blo_read_file_internal(fd, filename);

		/* ensures relinked images are not freed */
		blo_end_image_pointer_map(fd, oldmain);

		/* ensures relinked movie clips are not freed */
		blo_end_movieclip_pointer_map(fd, oldmain);

		/* ensures relinked sounds are not freed */
		blo_end_sound_pointer_map(fd, oldmain);

		/* Still in-use libraries have already been moved from oldmain to new mainlist,
		 * but oldmain itself shall *never* be 'transferred' to new mainlist! */
		BLI_assert(old_mainlist.first == oldmain);

		if (bfd && old_mainlist.first != old_mainlist.last) {
			/* Even though directly used libs have been already moved to new main, indirect ones have not.
			 * This is a bit annoying, but we have no choice but to keep them all for now - means some now unused
			 * data may remain in memory, but think we'll have to live with it. */
			Main *libmain, *libmain_next;
			Main *newmain = bfd->main;
			ListBase new_mainlist = {newmain, newmain};

			for (libmain = oldmain->next; libmain; libmain = libmain_next) {
				libmain_next = libmain->next;
				/* Note that LIB_INDIRECT does not work with libraries themselves, so we use non-NULL parent
				 * to detect indirect-linked ones... */
				if (libmain->curlib && (libmain->curlib->parent != NULL)) {
					BLI_remlink(&old_mainlist, libmain);
					BLI_addtail(&new_mainlist, libmain);
				}
				else {
#ifdef PRINT_DEBUG
					printf("Dropped Main for lib: %s\n", libmain->curlib->id.name);
#endif
				}
			}
			/* In any case, we need to move all lib datablocks themselves - those are 'first level data',
			 * getting rid of them would imply updating spaces & co to prevent invalid pointers access. */
			BLI_movelisttolist(&newmain->library, &oldmain->library);

			blo_join_main(&new_mainlist);
		}

		/* printf("Remaining mains/libs in oldmain: %d\n", BLI_listbase_count(&fd->old_mainlist) - 1); */

		/* That way, libs (aka mains) we did not reuse in new undone/redone state
		 * will be cleared together with oldmain... */
		blo_join_main(&old_mainlist);

		blo_freefiledata(fd);
	}

	return bfd;
}

/**
 * Frees a BlendFileData structure and *all* the data associated with it (the userdef data, and the main libblock data).
 *
 * \param bfd The structure to free.
 */
void BLO_blendfiledata_free(BlendFileData *bfd)
{
	if (bfd->main) {
		BKE_main_free(bfd->main);
	}

	if (bfd->user) {
		MEM_freeN(bfd->user);
	}

	MEM_freeN(bfd);
}